Abstract: By means of orientational observation in the field, flowering dynamic, breeding system, P/O and OCI of the two bamboo species, Shibataea chinensis and Arundinaria simonii f. heterophylla, were determined. The stigma receptivity was estimated by benzidine-H₂O₂, the pollen-ovule ratio, morphology of stigma were examined with microscopy, and bagging was used to examine the breeding system.The main results were as follows:the flower buds differentiated in October last year and bloomed in March this year for Shibataea chinensis. While the flower buds differentiated in March and bloomed in April for Arundinaria simonii f. heterophylla. Artificial pollination can improve the seed setting. The seeds could be harvested more or less every year. However, Shibataea chinensis never bore any seeds. The breeding system of Arundinaria simonii f. heterophylla is mainly outcrossing, but partly may be self-compatible.